Pierson,
Sorry for the delay..went out for a blast today in the 7 to the local golf club.. 😬
You will need to ring up Speedy cables and tell them that you want to convert your speedo to work off a front wheel speed sensor. They will give you a quote...not cheap mind but worth it . Six weeks later you will receive the converted speedo and a speed sensor. I then bought a sensor mount from Caterham here and took off the brake calliper from the off side front wheel. Then mount the sensor and wire it to the speedo with the supply,earth etc . I also got a new plug for the speedo from Speedy cables which made wiring it up very easy.
Next thing is calibration . Jack up the wheels and rotate the wheel . There is a small led on the sensor which should flash 4 times as it see the hub bolts . Adjust the position of the sensor until you see it. It was very critical..mine was about 0.5mm away from the bolts. Then tighten up the brake caliper bolts .
Speedy cables will send you some instructions on calibrating the speedo .. I will look later on what the calibration figure is..
More update later...SWMBO is calling..
Steve